Hundreds of demonstrators gathered in the Thai capital on Saturday evening to demand that authorities release some protest leaders from jail, defying an order on late Friday banning public gatherings in the city.
A youth-led protest movement sprang up last year calling for the resignation of Prime Minister Prayuth Chan-ocha, a former junta leader, and reform of the powerful monarchy. Thai courts have denied recent requests for bail for some of the jailed protest leaders.
"Release our friends," shouted the protesters in unison, as they gathered in front of a criminal court, which was surrounded by barbed wire. A water cannon truck could be seen behind the gates of the court.
"Abolish 112," they also said, referring to Thailand's lese majeste law, or Article 112 in the Thai criminal code, which prohibits anyone from insulting or defaming the king.
A few protesters burned photographs of the king at the rally. Separate groups also led two other protests at other locations in Bangkok.
Earlier on Saturday, police warned protesters that they risked being arrested and that police might use harsher measures if protesters became unruly.
"Protests are illegal. Anyone who joins or invites others to join is breaking the law," Piya Tavichai, deputy commissioner of Bangkok Metropolitan Police Bureau, told a news conference.
Police used rubber bullets for the first time last Sunday, as well as tear gas and water cannon to disperse protesters. Ten protesters and 26 police were injured.
In a podcast on Saturday morning, the prime minister urged Thais to respect the law and avoid conflict.
"We have to love each other and be united, not divided, and respect the law," said Prayuth, who first came to power after leading a military coup in 2014.
The Royal Palace has declined to directly comment on the protests, but Prayuth and government officials have said that criticism of the king is unlawful and inappropriate.